syzbot suspects this issue was fixed by commit:
commit 43016d02cf6e46edfc4696452251d34bba0c0435
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Mon May 3 11:51:15 2021 +0000
netfilter: arptables: use pernet ops struct during unregister
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=140478ffd00000
start commit: c3d8f220 Merge tag 'kbuild-fixes-v5.9' of git://git.kernel..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=bb68b9e8a8cc842f
dashboard link: https://syzkaller.appspot.com/bug?extid=35e70efb794757d7e175
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14f6602e900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1203cc61900000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: netfilter: arptables: use pernet ops struct during unregister
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
